My graphic design marketing campaign

[graphic designer]

who would be a good niche to try to contact potential customers for me ?

[shoestringventure]

You can try various freelance portals to find potential customers for you. There are some really grate freelance portals, where you can get good value for your services and you can also have regular flow of work. You can try elance.com or guru.com

[mtnjkwe]

I think you should work on your portfolio as that is what a potential client will base his decision to hire you or not.
I am a newbie in this designing business, and I used Create a Free Website , Free Flash Website Builder at Wix.com to build my portfolio and I am pretty satisified with it and I think others will agree with me. You can take a look at it here www.simplymartin.makes.it/
I also think your name should be your brand,so you will be marketing your name.

[TylerWoerner]

I would agree with mtnjkwe. I am a graphic designer as well. The first thing people ask to see is our portfolio, and then price. I think having a simple web page with both of those things will go really far. There are a lot of free to inexpensive solutions out there. If you PM me I can point you further in the right direction.